Roller mill



.April 30, 1940. A. E. HAwllvNsv-l l Y 2,199,340

ROLLER MILL Filed June 9, 195B 2 shets-sheet 1 Figui. Je

INVENTOR.

April 30, 1940.. A, E HAWK|N$ 2,199,340.

v ROLLER MILL Filed June 9, 1938 2 sheets-sheet 2 ,werf E. Haw/fm iPatented Apr. 30, 1940 UNITED STATESv ROLLER MILL Alberi E. Hawkins,wood-mage, N. J., mimmto J. M. Lehmann Co., Inc., New York, N. Y., acorporation of New York Application June 9, 1938, Serial No. 212,644

3 Claims.

This invention relates to roller mills, particularly to roll adjustingmeans for such mills, and has for an object the provision ofimprovements in this art. v

6 Often when roller mills are used for grinding pigments for paints,inks or the like or substances like cocoa or chocolate, it isdesirablerto have the rolls pressed together evenly along their lengthand also to have accurate information as to the l pressure between therolls so the degree of fineness of crushing can be determined andrepeated when desired in the future. Roller mills with hydraulic rolladjustment have been developed which, theoretically at least, satisfiedthese requirements.

The present invention aims to improve these hydraulically adjustedroller mills by providing simpler mechanism which gives greaterassurance of obtaining even roll adjustment of denitely predeterminedvalues and also to provide within one and the same mechanism, means forboth forcing the rolls together and for separating them. The inventionalso provides a. single control mechanism which acts evenly andsimultaneously on both ends of a roll.

'I'he objects and advantages of the invention will be understood fromthe following description of an illustrative embodiment of the inventionshown in the accompanying drawings, wherein:

Fig. 1 is a top plan view;

Fig. 2 is an end elevation; and y Fig. 3 is anenlarged vertical sectiontaken on the line 3-3 of Fig. 1.

In the drawings the numeral I0 designates a roller mill frame rotatablysupporting a roll II operating in xed bearings and a pair of rolls I2operating in adjustable bearings. The speciilc construction, as shown inFig. 3 comprises bearing blocks I3 slidable longitudinally in guides I4.The

4,0 rolls are driven by a motor M through suitable gears at each endgenerally indicated by the numeral I5. The gears are of the known typewhich will permit driving of the rolls in all adjusted positions andwhich are smooth and quiet in operation. 'I'he rolls are provided withparts I6 associated with the feeding mechanism and a discharge apron I1.Pipes I8 are shown for supplying cooling iluid to the rolls.

At each end of each adjustable cylinder the bearing block, as shown inFig. 3, is connected to a piston rod 20 by a pin 2 I. 'Ihe piston 22operates within a cylinder 23 secured tothe frame. 'Ihe piston is of thedouble-acting type subject to iluid pressure on either side. The pistonhas a larger area and hence is subject to greater pressure on the lsidefor forcing the rolls together and has smaller area and is subject tolesser pressure on the side for separating the rolls.

Means are provided for actuating the pistons 22,preferablymechanicalmeans acting through a hydraulic medium. Only one mechanical actuatingdevice is required, this being placed atene end of an adjustable rolland acting through fluid conduits upon the bearing adjusting piston atthe other end of the roll. 10

The actuating means hereinA disclosed comprises a control piston 25securedto a piston rod 26 and operable in an auxiliary cylinder".y 'I'hepiston 25 is also double acting, but both faces, which are approximatelythe same size, are much 5 smaller than either face of the piston 22 soas to give a lworking advantage to the piston 25. Conveniently thecylinder 2'I is formed in a separate casting 25 which is securedwithinthe cylinder 23. 20

The. piston rodI 26 is held against rotation by splining it, as at 29 bya pin and slot arrangement, within a bore in the piston rod 20. The rod26' is actuated by a rotatable sleeve 30 threaded in a member 3|, thesleeve being xed longitudi- 25 nally on the rod 26 between collars 32and 33 and being turned by a hand wheel 34.

'I'he pistons 22 and 25 and the piston rods 2li and 26 are made assecure against fluid leakage as possible. By using self-tighteningpacking 35, 30 36, 31 and 38 on the piston rod 2II, piston 22, piston25, andi piston rod 26 respectively and employing a heavy liquid likethick oil, the leakage may be kept at a minimum if not avoided alto-lgether. If lthere is a slight leakage the liquid 35 may be drained orreplenished as desired.

The fluid in the high pressure space 4I between the pistons 22 and 25may be in connection with the high pressure space behind the piston 22at the other end of the roll through a conduit 42.' 40 The fluid in thelow pressure space 43 behind the piston 25 is connected throughy theby-pass 44 with the space 45 on the opposite or withdrawal side of thepiston 22. Both spaces 43 and 45, or rather the by-pass 44 as shown, maybe con- 45 nected with the withdrawal space 45 of the piston 22 at theopposite end of the roll by a conduit 46.

The high pressure space 4Ir is connected with a pressure gauge 50 by apipe 5I. If desired a time.- pressure record-ing pressure gauge insteadof a 50 visual pressure gauge may be used.

The arrangement for both adjustable cylinders Amay be identical. Asshown in Fig. 1 the hand wheels 34 may be arranged at opposite cornersof the machine.

Desirably, means are provided for avoiding breakage if some large-orhardl object should accidentally pass through the rolls. This may beaccomplished by placing a relief valve, which is adapted to open whenthe pressure becomes unduly high, at some point in the high pressureside.

In operation, when the hand wheel u is turned in one direction pressureis built up in the space 4i between the pistons 25 and 22 to force bothends of the adjustable roll toward the xed roll. When the hand wheel uis turned in the opposite direction it relieves pressure in the space 4|and creates pressure in the spaces 4l and Il to withdraw the pistons 22at opposite ends of the roll. The construction is very simple, avoidsthe necessity for having separate pistons for advancing and retractingthe movable rolls, is reliable in operation and inexpensive tomanufacture.

While one embodiment of the invention has been described in detail inorder to illustrate the principles of the invention, it will beunderstood that the invention may be variously embodied within thelimits of the prior art and the scope of the subjoined claims.

I claim:

l. A roller mill comprising in combination, a fixed roll, an adjustableroll associated with vsaid xed roll, adjustable bearings for each end ofthe adjustable roll, a cylinder, a double acting piston mounted thereinadapted to be actuated in opposite directions by liquid in .oppositechambers in said cylinder, anextension cylinder'connected with saidmst-mentioned cylinder, a double acting piston in said second cylinderadapted to compress liquid in the cylinder cham- 1 bers on oppositesides thereof, one of the chambers of the rst cylinder opening directlyinto one of the chambers of the second cylinder, and the other chambersof the two cylinders being connected by aby-pass conduit, power meansfor actuating said second piston and through the liquid to actuate theirst piston, and means including .push-pull connections with saidadjustable bearings 4ior operating 'said bearings by said liquidactuating devices.

2. A roller mill comprising in combination, a ilxed roll, an adjustableroll associated with said iixed roll, adjustable bearings for each endof the adiustable roll, a cylinder, a double acting piston mountedtherein adapted to be actuated in opposite directions by liquid inopposite chambers insaid cylinder, .an extension cylinder connected withsaid mst-mentioned cylinder, a double acting piston in said secondcylinder adapted to compress liquid in the cylinder chambers on oppositesides thereof, one of the chambers of the iirst cylinder openingdirectly into one of the chambers of the second cylinder, and the otherchambers of the two cylinders being connected by a by-pass conduit,power means for actuating said second piston and through the liquidtoactuate the first piston, and means including push-pull connections withsaid adjustable bearings for operating said bearings by said liquidactuating devices, said power means comprising a manually operated handwheel and a screw connection between said hand wheel and a rod connectedto said second piston.

3. A roller mill comprising in combination, a fixed roll, an adjustableroll associated with said ilxed roll, adjustable bearings for each endof the adjustable roll, a cylinder, a double acting piston in saidcylinder, a push-pull connection 'between said piston and one of saidadjustable bearings, said connection holding said piston againstrotation in the cylinder, a. second cylinder connected with the iirst. adouble acting piston in the second cylinder, a splined rod between saidlpistons which also prevents rotation of the second piston but whichpermits longitudinal movement relative to the rst piston, and manualmeans including a hand Wheel and screw device for actuating the secondpiston and through a liquid operating the first piston.

ALBERT E. HAWKINS.

